[Due for payment 2025-05-08] [LOW] Optimize loops in Onyx

[roryabraham]

Problem

Loops in Onyx are using .forEach, which is no longer the best practice.

Solution

Update Onyx to use for...of loops, just as E/App does. This will lead to better code consistency, readability, and a marginal, low-level performance improvement.

Issue Owner

Current Issue Owner: @JmillsExpensify